A magnetic memory device (semiconductor integrated circuit device) in which a magnetoresistive element and a MOS transistor are integrated with each other on a semiconductor substrate has been proposed.
The above-described magnetoresistive element generally has a stacked structure which includes a storage layer having a variable magnetization direction, a reference layer having a fixed magnetization direction, and a tunnel barrier layer provided between the storage layer and the reference layer.
The reference layer includes two magnetic layers having the same magnetization direction as each other and one nonmagnetic layer provided between these two magnetic layers. To enhance the magnetic coupling between the two magnetic layers, the nonmagnetic layer should preferably be reduced in thickness. However, if the nonmagnetic layer is reduced in thickness, the characteristics of the reference layer will be degraded. Therefore, there has been demand for a magnetic memory device comprising a magnetoresistive element which can enhance the magnetic coupling between two magnetic layers of a reference layer without degrading the characteristics of the reference layer.